/*
author:杨文超
email:yangwenchao@keynection.cn
*/

#pragma once

#ifdef __cplusplus
extern "C" {
#endif
/*modbus_utils Utilities

This module contains some utility functions which can be used by
the application. It includes some special functions for working with
bitfields backed by a character array buffer.
*/

/*Function to set bits in a byte buffer.

This function allows the efficient use of an array to implement bitfields.
The array used for storing the bits must always be a multiple of two
bytes. Up to eight bits can be set or cleared in one operation.

@param ucByteBuf A buffer where the bit values are stored. Must be a
multiple of 2 bytes. No length checking is performed and if
usBitOffset / 8 is greater than the size of the buffer memory contents
is overwritten.
@param usBitOffset The starting address of the bits to set. The first
bit has the offset 0.
@param ucNBits Number of bits to modify. The value must always be smaller
than 8.
@param ucValues Thew new values for the bits. The value for the first bit
starting at <code>usBitOffset</code> is the LSB of the value
<code>ucValues</code>

\code
ucBits[2] = {0, 0};

// Set bit 4 to 1 (read: set 1 bit starting at bit offset 4 to value 1)
xMBUtilSetBits( ucBits, 4, 1, 1 );

// Set bit 7 to 1 and bit 8 to 0.
xMBUtilSetBits( ucBits, 7, 2, 0x01 );

// Set bits 8 - 11 to 0x05 and bits 12 - 15 to 0x0A;
xMBUtilSetBits( ucBits, 8, 8, 0x5A);
\endcode
*/
void            xMBUtilSetBits( UCHAR * ucByteBuf, USHORT usBitOffset,
                                UCHAR ucNBits, UCHAR ucValues );

/*Function to read bits in a byte buffer.

This function is used to extract up bit values from an array. Up to eight
bit values can be extracted in one step.

@param ucByteBuf A buffer where the bit values are stored.
@param usBitOffset The starting address of the bits to set. The first
bit has the offset 0.
@param ucNBits Number of bits to modify. The value must always be smaller
than 8.

\code
UCHAR ucBits[2] = {0, 0};
UCHAR ucResult;

// Extract the bits 3 - 10.
ucResult = xMBUtilGetBits( ucBits, 3, 8 );
\endcode
*/
UCHAR           xMBUtilGetBits( UCHAR * ucByteBuf, USHORT usBitOffset,
                                UCHAR ucNBits );

#ifdef __cplusplus
}
#endif

